Thursday, February 21, 2008

Google Maps in the Sciences

The Google Maps API is beginning to be used widely within academia to help scientists and social scientists visualise data. Analysing very large datasets has always been a problem for scientists but Google Maps is providing an effective tool for researchers to visually represent and compare large data sets that contain geographic elements.

The Centre for Advanced Spatial Analysis (CASA) at University College London is at the forefront of research into spatial modelling and visualisation for social scientists and has a number of interesting Google Maps projects.

One such project is The London Profiler, a web site that enables users to build up a picture of the geo-demographics of Greater London from data on population attributes such as cultural/ethnicity, deprivation and crime etc.

Each of the various data sets can be turned on or off as layers on a Google Map. This means that all the layers can be compared with each other. The map includes a layer from Nestoria that shows houses currently for sale or rent in London. Comparing the various layers with the Nestoria layer quickly confirms that there is a close co-relation with house prices in London and levels of crime and educational attainment.

Whilst The London Profiler is obviously a great way for social scientists to analyse the geo-demographics of London it will also be of great interest for anyone who lives in London. The first thing I did was check the health layer for my neighbourhood and quickly noticed that heart attacks are very common in my area. Obviously that is one reason why the house prices are relatively cheap here.

The London Profiler was built with CASA’s GMapCreator. The GMAPCreator is a Java application that automatically creates Google Maps websites from Shapefiles containing polygon areas. It creates tiles from user entered Shapefiles that are then overlaid on a Google Map. This is particularly effective if you have a large amount of data you want to map and you also want to protect your data. Because the created maps are built from pre-rendered tiles the raw data is never stored on the Internet. This then is a safe way of sharing a map without giving away the raw data used to create it.

Maps built using the GMapCreator can then be added to CASA’s MapTube. MapTube is a website for sharing maps created with the Google Map Creator software. Any map shared with MapTube can be overlaid with any other map on MapTube.

The main principle of MapTube is that shared maps can be overlaid on each other to compare data visually. For example, a map of income levels can be overlaid on a map of educational attainment so that comparisons can be made between educational achievement and wealth. In essence through using MapTube you can create your own version of The London Profiler but for the location of your choice.

Another London educational institute that is using Google Maps to visually represent data is Imperial College London. Their website Spatialepidemiology.net is using Google Maps to provide an interface for the display and analysis of infectious disease epidemiological data, including molecular data.

Mashing together genetic and epidemiological data on Google Maps provides them with an important new way of analysing and displaying epidemiological data. They have so far created a number of maps, each one tracking a different virulent or antibiotic-resistant strain of one of the major pathogens. Links to the maps are indexed here.